fix(sdk): recover the in-flight message on a preloaded chat.agent retry

A preloaded chat.agent run (started via transport.preload) that retried after an out-of-memory error dropped the message it was processing at crash time. Boot recovery restores the in-flight message into the dispatch queue and advances the .in cursor past it, but the preload branch fired onPreload and waited for a first message without draining that queue, so the recovered message was stranded behind the advanced cursor and the run sat waiting. The preload branch now dispatches a recovered message as the first turn before waiting.

Includes a full-stack e2e that reproduces the drop (preloaded run, OOM on attempt 1, in-flight message on .in) and passes with the fix.

Author: ericallam

.changeset/chat-agent-preload-oom-recovery.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/sdk": patch
+---
+
+Fix a preloaded `chat.agent` run dropping an in-flight message when it retries after an out-of-memory error. The message being processed when the run hit the OOM is now recovered and re-run on the retry, instead of being skipped while the run waited for a new message.

apps/webapp/test/session-agent.e2e.test.ts

@@ -1415,7 +1415,7 @@ describe("session agent e2e (real chat.agent loop)", () => {
     }
   });
 
-  it("EA21: an OOM fails the run; the attempt-2 retry recovers the message", async () => {
+  it("EA21: a preloaded run's OOM retry recovers the in-flight message", async () => {
     const { addressingKey, token, apiKey, baseUrl } = await setupSession(testOomChatAgent.id);
     const runId = `run_oom_${addressingKey}`;
 
@@ -1456,7 +1456,6 @@ describe("session agent e2e (real chat.agent loop)", () => {
       modelLocal: testChatModelLocal,
       runId,
       attemptNumber: 2,
-      continuation: true,
     });
     try {
       const { parts } = await collectSessionOut({

packages/trigger-sdk/src/v3/ai.ts

@@ -6062,8 +6062,21 @@ function chatAgent<
           );
         }
 
+        /**
+         * A retry (e.g. OOM) or continuation whose boot recovery restored an
+         * in-flight `.in` message dispatches it as the first turn. The recovery
+         * block already advanced the `.in` cursor past the recovered message,
+         * so the preload wait below would otherwise strand it (the run would
+         * sit waiting for a "first message" that already arrived).
+         */
+        let dispatchedRecoveredFirstTurn = false;
+        if (preloaded && bootInjectedQueue.length > 0) {
+          currentWirePayload = bootInjectedQueue.shift()!;
+          dispatchedRecoveredFirstTurn = true;
+        }
+
         // Handle preloaded runs — fire onPreload, then wait for the first real message
-        if (preloaded) {
+        if (preloaded && !dispatchedRecoveredFirstTurn) {
           if (activeSpan) {
             activeSpan.setAttribute("chat.preloaded", true);
           }